KENNEDY SPACE CENTER, FLA. - Space Shuttle Discovery, atop a Mobile Launcher Platform (MLP), crawls toward Launch Complex 39B. First motion out of the Vehicle Assembly Building occurred at 2:04 p.m. EDT. The rollout marks a major milestone in the Space Shuttle Program?s Return to Flight. The MLP is moved by a Crawler-Transporter underneath. A banner signed by KSC employees who helped process the orbiter for launch, proclaiming "We're Behind You, Discovery!," is affixed to the MLP. Launch of Discovery on its Return to Flight mission, STS-114, is targeted for May 15 with a launch window that extends to June 3. During its 12-day mission, Discovery?s seven-person crew will test new hardware and techniques to improve Shuttle safety, as well as deliver supplies to the International Space Station.